K Series Nuts

This product offers a permanent female thread in sheet steel and in plastic applications that are too thin to be tapped by conventional methods.

K Series Nuts

Designed specifically for use in applications with a minimum sheet thickness of 1mm, when installed the K Series Nut offers a metric female thread for attaching equivalent metric externally threaded fasteners. K Series Nuts can be easily installed into the parent material without the need for specialist tooling.

Available ex-stock, we offer K Series Nuts in all of the standard spigot lengths and we now also offer intermediate and long spigot lengths ex-stock for use in thicker sheet steel or plastic applications. 

Materials Icon (2)


  • C1022 carbon steel
  • Case hardened to a minimum of Hv0.3 610
  • Tested to ISO 898 
  • Stainless steel finishes can be supplied to order 

Product Features Icon (2)

Product Features

  • Sizes to suit most applications
  • M2.5 - M20 sizes ex-stock
  • No special tooling required
  • One head style - Hexagon
  • Three spigot lengths available ex. stock: standard, intermediate & long
  • High torsional resistance
  • High pullout resistance
  • Zinc Plated (CR3) as standard
  • Stainless Steel supplied to order
  • Stock ready for immediate despatch

Product Application (2)


  • When inserted the underhead shank serrations of the K Series Nuts provide a permanent thread with a high prevailing torque and a resistance to turning.

Product Installation

K Series Installation 1


Prior to installation the K Series Nut must be aligned squarely with the pre-drilled or pre-pressed hole in the host material.

K Series Installation 2


Ideally using a punch the K Series Nut is pressed into the host material.
As the nut rotates it bites into the wall of the sheet causing the host material to flow around the spigot of the nut.
The slanted serrations provide a secure fit with a strong resistance to rotation. 

K Series Installation 3


When the K Series Nut has been installed an externally threaded fastener can be used to join the two materials together.
The K Series Nut is secured from the serrated side.